I have connected my studio controller (Kurzweil PC3x) via SPDIF to my audio interface so that, in addition to sending midi to my DAW through usb, I can also audition and record sounds from my controller workstation. However, with all volumes at full (including on the controller, on the monitors, and on the interface), the output volume is quite low. It is audible but barely and there is nowhere else to increase the volume. Any ideas about what I could be doing incorrectly? The volume through headphones is normal, as is the volume of any other sounds coming through the interface and monitors.
PS. Yes, there is a software mixer for the interface but both the SPDIF input and the analog master output are both turned all the way up. I am on vista x64 with Q6600 and 8 GB ram.